AIRFLOW Measurement Systems

  • AF36            
  • AF16S            
  • AV-1            
  • Flowlab         

AF36 Airflow Measurement System

AF36 CabinetThe flagship product of Fleming & Associates Calibration, the AF36 is the industry standard in dynamic airflow measurement for gas turbine components. Since its introduction the AF36 has conformed to the originaln design parameters of being self-contained, self-calibrating, efficient and providing repeatable and accurate test results. Over 120 AF36 Measurement Systems are being used by industry worldwide.

Fleming & Associates Calibration continues to refine, update and upgrade the AF36 design.

The purpose of the AF36 Airflow Measurement System is to determine the aerodynamic area of various components such as gas turbine nozzles, nozzle segments, wheels, combustion liners, and other similar components. The area is measured dynamically through transfer standards, air pressures, temperatures and blower speeds. This is accomplished by the system adjusting blower speed to obtain the desired differential pressure across the component being measured, and then calculating the area as a function blower speed and the other above measurements.

The primary advantages of airflow testing over mechanical gauging are that airflow testing requires only a small fraction of the time required to gauge a component mechanically, and avoids the expense of calibration and repair of gauges. It should also be noted that historically, when mechanical gauging results do not agree with Effective Flow Area (EFA) test results produced with the AF36, EFA results provide a better indicator of engine performance.

Adaptors are required for seating the component to be measured onto the AF36, and channeling the air smoothly into the component being measured. A series of easy-to-change mounting rings allows for a wide range of adaptor diameters. A large swing-clamp on the cabinet simplifies the mounting of most components. Many adaptors are already available, and adaptors for most components can be furnished with the equipment or ordered at any time. Accuracy of measurements is strongly influenced by adaptor design and manufacture, and Fleming & Associates has been leading the industry in adaptor design for decades.

A computerized interface system controller, with Windows XP platform software and a touch screen operator interface control the Airflow Measurement System. Fleming & Associates proprietary software provides the selection of three different pressures across the component: 0.5” (12.7 mm), 1.0” (25.4 mm), and 5.0” (127mm) H2O. The system is calibrated at the factory at these pressures using ASME nozzles (upon request the system may be calibrated and configured to operate at other pressures). The main blower system consists of a positive displacement blower and an AC motor speed control. The main blower speed controls the airflow in the main flow system in order to maintain the desired pressure drop during measurement. Since the pressure drop across the test component is constant, area is proportional to flow.

In order to calculate area, sensor measurements are collected and processed by the computerized interface system. The sensors include six (6) thermostats, linearized with a measurement specific linearizing circuit, a differential pressure transducer, an additional transducer to measure atmospheric pressure, and a humidity sensor to warn the operator of excessively high humidity.

The AF36 Airflow Measurement System is calibrated using transfer standards and collecting the blower speed, temperatures and pressures associated with the system bringing fixed differential pressure across the transfer standard. After several transfer standards have been measured an assessment is done to determine the blower’s characteristics. The use of Master components is highly recommended. Master components have two functions in the measurement process: they are used to verify the stability of Airflow Measurement System, and they provide compensation in the measurement process.

Historically the AF36 has gone through a number of design improvements since it was introduced by August Fleming in 1972. Today’s version is a computerized double blower system that is highly accurate, versatile and durable. Of the more than 136 Air Flow Systems produced, more than 120 are still in service. Fleming & Associates Calibration expects the working life span of a new AF36 to be at least 15 years.

The AF36 is a single, self-contained unit that is portable and can be moved with a fork truck. The unit is electrically driven. The AF36 Airflow Measurement System can be operated in both forward and reverse directions. The AF36's ability to run in reverse enables easy measurement of combustion liner features. The tooling on some component nozzles is also more readily adaptable to running in the reverse direction. The AF36 cabinet meets NEMA 1 enclosure requirements. The AF36 is built to U.L. and N.E.C. standards and can be U.L. certified if required, and is CE compliant.

AF16S Airflow Measurement System

AF16The AF16 is used to determine the aerodynamic area of various gas turbine components using shop air. The entire unit is designed to sit on a workbench. It is similar to the AF36 but, due to its requirement for shop air, it is not self-contained. The Instrument Cabinet is modular and compatible with the AV-1.

The purpose of the AF16S Airflow Measurement System is to determine the aerodynamic area of various components such as gas turbine nozzles, nozzle segments, wheels, combustion liners, and other similar components. The area is measured from airflow pressure differentials. This is accomplished by the AF16S channeling air over or through the test component that leads to the determination of the airflow area for the component being inspected.

The AF16S operates on shop air and 120/240 VAC, but is otherwise self-contained. Due to its short cycle time, the AF16S is especially suited for obtaining area measurements of components such as nozzle segments in a high production environment. The system's basic components consist of a plenum chamber, and instrument cabinet and a computerized system controller. The instrument cabinet may also be used in tandem with the Fleming AV1 Mass Airflow Measurement System. The entire system can be installed on a standard 36" x 72" (91.4 x 183 cm) workbench. The AF16S is designed to measure areas under 3 square inches (193.5 cm2).

Adaptors are required for seating the component to be measured onto the AF16S, and channeling the air smoothly into the component being measured. An easy-to-change mounting ring allow for a range of adaptors. Many adaptors are already available, and adaptors for most components can be furnished with the equipment or ordered at any time.

Shop air supply flows through a control valve into the supply plenum. The air then enters a sonic nozzle (venturi) which discharges into the main plenum and thus through the component being measured. A ball valve is provided enabling complete shut-off. The control valve regulates the pressure in the sonic nozzle's supply plenum. There are five sonic nozzles in the AF16S, each used for measuring a different area range. The sonic nozzle is used to measure mass flow into the main plenum. The computerized control system controls the pressure in the main plenum automatically. The component's area is determined by the mass flow through the sonic nozzle required to achieve the specified pressure in the main plenum (upstream of the component). The use of sonic nozzles can provide another method of traceability. The control software supports automated correlation to any linear and many non-linear measurement units.

The chamber size is 14.8" (35.6 cm) diameter by 18" (45.7 cm) long, with mounting for 12” (30.5 cm) and 16” (40.6 cm) outside diameter flanged adaptors (11" [27.9 cm] and 15" [38.1 cm] openings). The AF16S has the same mounting for adaptors as the 12" (30.5 cm) and 16" (40.6 cm) diameter mounting rings for the Fleming AF36 Airflow Measurement System. Hook clamps, used to hold fixtures, are a convenient and efficient method of mounting. An O-ring on the face of the mounting makes a reliable and durable seal between the plenum and the adaptor. Baffling assures good flow distribution in the plenum.

The AF16S has computerized readout and controls via a controller system with Fleming & Associates Calibration Software. Electronics and instrumentation is supplied in a cabinet separate from the plenum chamber. The instrumentation cabinet is approximately 16" x 18" x 7" (40.6 x 45.7 x 17.8 cm). The instrument cabinet is interfaced to a controller provided with the equipment.

The instrument cabinet is compatible with and can be used in tandem with the Fleming & Associates Calibration AV1 Mass Airflow Measurement System.

AV-1 Mass Airflow Measurement System

The AV-1 is a high-precision system for measuring mass flow of air. It also uses shop air to produce measurements. The Instrument Cabinet is modular and compatible with the AF16. It can be effectively coupled with the AF16 to provide a wide range of test parameters.

The purpose of the AV1 Mass Airflow Measurement System is to determine the total airflow of various components such as gas turbine nozzles, nozzle segments, wheels, combustion liners, and other similar components. This is measured from airflow pressure differentials, and is accomplished by the AV1 channeling air over and/or through the test component, which leads to the determination of the airflow area for the component being inspected. The AV1 has been designed with the necessary flexibility to measure a variety of components. It is a high precision system for measuring mass flow of air specifically designed for the use in the gas turbine industry.

Mass airflow is obtained by utilizing a calibrated sonic nozzle positioned upstream (i.e. in series with) of the fixture and component being evaluated. A separate port located on the fixture is used to sense the actual pressure at the part. A regulator is used to adjust the pressure upstream of the sonic nozzle, which in turn varies the P3 Part Pressure. Once the required P3 Part Pressure is obtained the operator waits until the mass flow rate meter has stabilized and then records the reading.

The AV1 has a modular design, and the instrument cabinet is compatible and can also accommodate and is used in tandem with the Fleming & Associates Calibration AF-16S Airflow Measurement System. Inquire for more details.

The AV1 has computerized readout and controls via a personal computer with Fleming & Associates Calibration Software. Electronics and instrumentation is supplied in a cabinet separate from the meter-run. The instrumentation cabinet is approximately 16" x 18" x 7", and the instrument cabinet is interfaced to a computerized control system proved with the equipment.

Fleming Flowlab

Fleming FlowlabThe Fleming Flowlab is a highly adaptable and flexible airflow measurement tool.

Flowlab can be used to dynamically measure the area of many components, including the difficult-to-measure cooling flows on many components. 

 

 


The system is equipped with the following features:

Four Flow Ports, each consisting of a pressure connection and pressure sense connections. 
Each port can be connected to a different fixture or a different flow passage of a fixture.

Pneumatic vise support

Sonic Nozzles (Critical Flow Elements)

  • Eight sonic nozzles calibrated to +/-0.5% (NIST traceable) are provided with the standard configurations. 
    If flows outside the standard range are required custom configurations are available. 
  • Standard Sonic Nozzle Diameters:
    0.2500, 0.1770, 0.1250, 0.0880, 0.0620, 0.0440, 0.0310, 0.0210

OEM Specifications Supported by the FlowLab Software

  • Pratt & Whitney CPW 916, 322-D, ASQ-C
  • General Electric E50TF218
    (Other manufacture specifications can be provided upon request)

Power Supply

  • 0.5 KVA
    120/240 VAX +/-10% 47/63 Hz

Shop Air Requirements

  • Dew Point…………………………………………….-40°F
  • Pressure………………………………….85 to 100 PSIG (585 to 690 K Pascals)
  • Max Flow Rate (at 0.2 PPS) 120 SCFM (standard feet³/minute)
  • [70°F, 14.696 PSIA] 2400 SCLM (standard liters³/minute)

Accuracy and Range

  • Range……………………………..0.000235 to 0.1442 PPS (Pounds per Second)
  • Note:  Non-standard Sonic Nozzles can be substituted to extend range if desired.
  • Accuracy………………………..+/-1% NIST traceable flow rate
  • Repeatability………………………………+/- 0.25%
  • Warm up time required:  30 minutes

Pressure Transducers

  • The most accurate pressure transducers available are used. 
    The accuracy of these transducers is +/- 0.03% FS